According to the present invention, fecal waste refers to solid and liquid excrement of every type, for example, manure-urine mixtures with and without interspersion, such as accumulates with the large-scale handling of domestic animals. Such fecal waste is usually very inhomogeneous, since strong suspended layers, or also, however, solid top layers, often form, whereby the transport to and the deposition on agriculturally used areas, which is very desirable because of the nutrients contained therein, leads to further difficulties. Fecal waste burdens the environment with a strong, rank, and long-lasting odor. Further, in the case of fecal decay, such as usually occurs during storage, a large number of materials strongly toxic to roots develop in considerable amounts, of which the exact compositions and interactions are still not known in particular. These decomposition products probably include phenolic compounds (from blood and gall), lignin components, decomposition products of albumen (amino acids and amines), as well as organic acids (e.g., butyric acid, propionic acid). One substance strongly toxic to plant roots is probably also ammonium carbonate, which results from the decomposition of urinary materials.
The stoppage and impairment of root growth caused by these substances reduces the capacity of the plants to absorb nutrients so strongly that fecal substances are generally considered as erratic and unreliable fertilizing agents in agriculture; their reactions are calculated only with difficulty, since they depend greatly on temperature, dampness, the condition of the soil, etc.
Further, fecal waste, especially in liquid form, can be used only with great disadvantages in green areas:
firstly, because the green plant parts and the root systems of flat-rooting plants are damaged, and
further, because grazing animals requiring green food refuse food fertilized in this way.
For that reason, fecal waste is generally not used during the vegetation period, but rather after the end of the vegetation period in the fall or the winter. This sort of practice, however, has the disadvantage that an uncontrollable nitrification of the ammonium nitrogen occurs, since the nitrate nitrogen formed outside of the vegetation period cannot be absorbed by the plants, and goes into the ground water with rain or melted snow. Thus, the fall and winter use of fecal waste on large agricultural areas represents today one of the most important factors in the contamination of ground water with nitrate and organic components. Furthermore, potassium is washed out and phosphate is set in the soil as tricalcium phosphate.
Finally, the untreated fecal waste contains slimy substances which obstruct the fine pores of the soil, whereby the soil's receptive capability is impaired. The fecal matter can, with intensive fertilization, get into the surface water and contaminate it, not least of all with pathogenic germs.